So this is not one of those options which exists where you would expect to find it (checkout options, right?).
Here’s how we disable the “Checkout with Multiple Addresses” link.
1. Log in to Magento’s Admin Panel.
2. Navigate to System > Configuration > Sales > Shipping Settings.
3. Expand the Options header.
4. Set the option “Allow Shipping to Multiple Addresses” to “No”.
5. Done.
Happy checkouts!
